Hyun-soo Oh

Thermal stability dependence on the stacking order and thickness ratio of the CoPt–TiO2∕CoCrPt–SiO2 stacked media

Thermal stability of the present CoCrPt–SiO2 media becomes a more critical issue as recording density steadily increases. In the present study, thermal stability of the stacked media composed of high Ku CoPt–TiO2 and normal Ku CoCrPt–SiO2 was studied by changing stacking order and thickness of each layer while keeping a constant total thickness. When the CoPt–TiO2 layer was placed under the CoCrPt–SiO2 layer, negative nucleation field and coercivity increased much more than those of the reverse stacking case. Thermal stability of the CoPt–TiO2 bottom group was superior to that of the CoCrPt–SiO2 bottom group when measured by a spin stand.

Ru/NiFeX/Si seedlayer to attain finer grains in CoCrPt-SiO2 perpendicular magnetic recording layer

In this study, we propose thin NiFeX/Si seedlayer for getting good crystallographic structure as well as finer grains of thin Ru layer. However, relatively thick thickness in the Ru layer deposited onto bcc-like thin Ta layer is needed for attaining the required crystallographic properties. Such thick intermediate layer causes to degrade the recording performances owing to deteriorated writing field gradient.